45-|-27-(-25)-x|=-7+27
45-|-2-x|=20
|-2-x|=45-20
|-2-x|=25
=>-2-x=+25
TH1:
-2-x=25
x=-2-25
x=-27
TH2:
-2-x=-25
x=-2-(-25)
x=23
Vay :x=-27 hoạc 23
= 45 - | 2 - x | = 20
| 2 - x | = 45 - 20 = 25
TH1
=> 2 - x = 25
=> x = 2 - 25 = -23
TH2
=> 2 - x = -25
=> x = 2 - (-25) = 27
= x = { -23 ; 27 }